Indexing broach mechanism.



R. R. LAPO INTE.

moexma BROACH MECHANISM.

witnesses.

, inventor Raf 6h R. La bole.

his A orwey mJRIALPI-I It. LAPOINTE, F HUDSON, MASSACHUSETTS, ASSIGNOR TO THE LAiPOINTE teasers.

llO

MACHINE TOOL COMPANY, OF HUDSON, MASSACHUSETTS, A

MAINE.

CORPORATION OF I INDEXING BROACI-I MECHANISM,

S pecificati ers Patent. pafnh d J l f3 191 3;;

' Application filed. July 27,1914. Serial no. 853,324.

To all whom itmay concern: 1

Be it lmown that T, RALPH R. lLAroINTn, a citizen of the United States, and resident of Hudson, county of Middlesex, State of Massachusetts, have invented an Improvev ment in Indexing Broach Mechanisms, of

-which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The present'invention relatesto broaching mechanism and particularly to devices adapted to hold a'work piece successively in a series of angularly indexed positions,

permitting the same to'be turned about its center exact predetermined distances for successive operations of the breaching tool ,whereby certain operations requirmg precision of adjustment such as the production of gears by the cutting of aliquot parts thereof at each stroke. 'The prime object of the invention is to provide mechanism having a capacity of convenient and quick adjustment of the work piece to successive angular positions, the parts being so ar? ranged that it is practically impossible to set the work piece in any except the accurate position. A further object ofthe 1nvention is to provide improved means for relieving the broach on the return stroke. The above and other objects and features of the invention will be better understood out in the appended claims.

from the following detailed description taken in connection with the accompanying drawings and will be thereafter pointed Referring to the drawings:

1 V Figure 1' is a front elevation ofa broach ing mechanism having my embodied therein;

Figs 2 is .a central longitudinal vertical section thereof; and

Fig. 3 is a detail showing a form of broach adapted for the broachlng of-gears naliquot parts.

-The face plate of the broaching machine is indicated at 10 with a usual reducing bushing ll'set inthe central aperture thereof. A second bushing 12 having a work supporting sleeve 13 projected at the front thereof is fitted in the bushing 11, the broach 14 being guided through this nner bushing or work support. 'The broach 14 has" its shank engaged by a transverse key 15 with a connection 16 to the reciprocating improvements I .tively-engaged. In this way after the dog 25 isonce clamped to the work piece and the working head of the machine (not shown), the seating of the broach shank in the socket in this connection being a slightly loose one for a purpose now to be explained. The

connection 16 has a collar 17 fixed thereon by means of a set screw 18, this collar proectmg beyond the end of the connection 16 and havlng an eye bolt 19 transversely slidable therethrough, the eye 20 of which takes around the shank of the broach and there being a coilspring 21 encircling this eye bolt with a backing against .the collar 17 and pressing against a nut 22 at the outer.

end of said bolt with the result that thisbottom of the out just made but will clear the same so that the broach will move back freely.

To provide for indexing-the work according to my invention, I provide an index plate 23 suitably fixed on the face plate or on the reducing bushingll thereof, this index plate having any suitable number of peripheral'notches or insets 24 therein, these being shown as eight in number and equally spaced apart. The work piece amounted-on the work supporting collar 13 is embraced and clamped by a dog 25, this clamping-be- .ing shown as efiected by a screw bolt 26.

The dog 25 has a radial arm 27" equipped -with a pin 28 having an inwardly projecting portion 29 adapted to fit within any one of the .notches 24 with which it may be selecpin'28 adjusted in one of the notches '29, the'first'broach out may be made, and thereafter any" required number of succeeding "cuts made either one-eighth, one-fourth or one-half acircumference angulaily from the, first may be cut according as the pin 28 is set into the next or one: of the succeeding" notches-24E. This capability, of exact angular adjustment of the .work piece with reference to the broach is valuable and useful in various kinds of operations such as the cutting of -multiple key ways in gears and hubs, but

it finds a peculiar and special utility in the cutting of internal gears which are too large or the teeth too deep to be cut complete at a single broaching operation. In this case the broach can be formed as seen at to cut a predetermined aliquot part of a gear at a single operation and then the work piece 6 being turned a precise angular distance from its first position having in mind the total number of teeth in the gear, and the aliquot part thereof already produced, and the work piece is then set in its next position ready for the cutting of the next aliquot part of its teeth. In this way by successive indexing the complete gear is very quickly and economically produced. I preferably providea wedge element as seen at 31as the immediate backing of the broach, which is inserted between the back thereof and the adjacent wall of the passage in the work supporting collar 13. This wedge is of course selected with reference to the character of broach and the nature of the cut to be produced and it may be withdrawn after the out so as to permit a greater freedom of action to the spring 21 in clearing thebroach teeth on the return stroke. I am aware that the invention can be embodied as to its several features in other specific forms than that shown and I therefore desire the present form to be considered as illustrative and 7.

not restrictive and refer to the appended claims rather thanto the foregoing description to indicate the scope of the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combinationwith a broaching machine having a face plate fixed' to the bed and said index plate, said face plate be ing equipped with a bushing also passing through said index plate with an extension to constitute asupport for the work piece, a broach fitted to operate in said bushing and on a work piece held thereby, and a clamping dog adapted to grip the work and havthrough said index plate, and a'clamping dog having a collar adapted to slip over the work and equipped with a radial arm having a pin adapted to selectively engage the recesses of the index plate for the purpose stated. I 8. Broaching apparatus, comprising an index plate, a work clamping dog having an arm in cooperative relation with said index plate, said armand said index plate having cooperative means for holding the work in any one of a predetermined series of angular positions, and a broach mounted for reciprocation in operative relation to a work piece clamped by said dog, said broach having its operative portion formed as a gear segment for broaching an aliquot part of a gear at each operative movement.

In testimony whereof, Ihave signed my name to this specification in the presence of two subscribing witnesses.

RALPH R. LAPOINTE. Witnesses I PERCY W. Omens, ARTHUR F. RANDALL. 

